Jim Byrnes Thickness Sander Operation Tips

[ChrisLBren]

Hi Group,

 

I would appreciate some operational tips here.  I am sure this is my fault not the tools - sometimes I am experiencing dips inthe 2  inch wide by 24 inch long plank I am dimensioning (probably from the drum of the sander).  Usually they only about a 1/8 of an inch wide or so accross the plank so I cut around my parts around it which wastes wood.

 

Is this a feed issue or am I trying to take off too much wood in one swipe ?  

 

I am reducing boards approx 6.75 mm thick to 5.6 mm final dimension.  

 

Thanks much,

Chris

Edited August 25, 2022 by ChrisLBren

[druxey]

The most likely reason for the groove is that the tip end of the plank drops as it comes off the outfeed table. Two solutions: One, hold the outfed plank close to the lip of the outfeed table, not its far end. Two, construct an extension to the outfeed side to support longer stock.

[mtaylor]

While I don't have the Byrnes, I find that speed and feed rate play a factor as well as depth.  My guess if you feel speed and feed are good, lessen depth.  Also, check that the wood isn't tilting particularly near the end of the sheet.  I made an extension for my sander to stop that.  It's basically just a block of wood as high as the bed and sits on the output side.

 

Edit.. I see Druxey and I cross posted.  Do try the output side extension. 

[Justin P.]

I haven't tried bits that are that long, but have found that success comes when not being really aggressive.   I take more passes that take less material.  Also mounting the paper and holding your work carefully helps a lot.  I usually need two hands to run a piece successfully.  One feeding or holding a push stick and the other guiding / holding the piece flat against the bed as it comes out the other end.   Most of my errors happen near the end of the feed so the opposing hand becomes critical to keep the work from being manipulated by the drum.   

 

You might also try sequencing your mill work differently.   For instance, I usually rough cut my work before the thickness sander - which is likely why Ive never had to feed 24" stock.

 

 

[allanyed]

If you feel the drum starting to stall or labor, you are taking off too much at a time.  If not, that probably is not the issue. Do you have a vacuum attached to take away the sawdust?  If you don't, depending on speed of the wood passing through, which should be steady as mentioned by Mark, it can build up on the board if you stop or slow down on pushing the wood through and cause this problem.   Also, be sure the sandpaper is on the drum tight so there is no bump.   Hopefully it is not a bearing issue.

Allan

 

 

[gjdale]

I have found that any pause in the feed rate will likely cause this issue, so as suggested above a steady, consistent feed rate with minimal “depth of cut” might help. More passes might mean more time, but it also means lower likelihood of issues.

[No Idea]

Just seen this thread and I used to have the same problem when I first got my thickness sander.  A few years later and I now know that it was just the way I was using it and not being familiar with its use.

 

So here's what I do - As soon as the wood being fed through pops out on the machined side I put my thumb on it to keep it tight to the feed table.  The reason I used to get dips was because I allowed the wood to raise slightly off of the bed. 

 

I feed through by hand using a constant pressure on the sanding drum and let the drum do the work.  I only use a feed through stick at the very last moment - I also use the widest stick that I have to keep the piece square to the sanding drum.

 

Also a 24" piece creates a lot of weight at the end of the sanding run as so much of it is unsupported once machined.  Just use loads of thumb pressure to keep it all flat and you will get the piece that you need.

 

Also as wood tends to cup - swap the plank around end to end and and turn it over often.  I have found that this method gives me the precise results that I want time after time.  I have removed 3mm in thickness with no issues at all except for the painful loss of so much great wood to saw dust!!!

[ChrisLBren]

Thanks for the tips everyone.  As a matter of fact just finished reducing some pear 1mm for more frames (32 completed and counting).  I used a combination of the Proxxon Planer and Brynes thickness sander for the final .5mm.  Cutting the boards in half to 12 inch lengths helped as well as being conscious of the feed rate and applying constant pressure to the board on the feed table.  It worked great - my sander has course paper on one side which I used to get the billet to almost final dimension and finished with the other fine side.